Malicious PDF — malware analysis report

Static analysis result for SHA-256 c435e7b895dad5a8…

MALICIOUS

PDF

70.1 KB Created: 2021-09-15 10:11:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d82bfec14a69116ea491cbfa413b3b19 SHA-1: c7dd4f8445bb3f61b0cbab6e57a86dd0c5a608c1 SHA-256: c435e7b895dad5a85b11162ab156582ce887d136845d1516bd303df1355a633a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs that point to various domains, many of which are flagged as link farms on disposable or potentially compromised hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The structure suggests the PDF itself is not the final payload but a lure to external, untrusted resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://archism.ru/uplcv?utm_term=osu+droid+maps PDF link annotation
    • https://abisspaandboutique.com/nbloom/fckuploads/file/dudawigogiriwilul.pdfIn PDF document text
    • https://samoinstitute.mn/uploads/assets/file/wujuv.pdfIn PDF document text
    • http://magdrywall.com/project-new/christianbook/upload_images/file/55216534901.pdfIn PDF document text
    • http://ty-universe.com/image/files/20210902_150028.pdfIn PDF document text
    • https://studiovizia.com/webroot/img/content/files/98460840618.pdfIn PDF document text
    • http://riasztoszolnok.hu/admin/fck_upload/file/68049451436.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/61dbc4f734ea6ccb8da1bcdb6414692e/9713174439.pdfIn PDF document text
    • http://jubangh.com/Upload/FckUpload/20210910file///53961292938.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/risarox.pdfIn PDF document text
    • http://thesprotia.gr/uploads/file/mudemetoxeju.pdfIn PDF document text
    • https://sunsetlearningcenter.com/userfiles/file/rozakopemujifagefipi.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed4ca0b55a---57369076040.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f861218ae1---kegemo.pdfIn PDF document text
    • http://randygordonlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/31750605653.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/jusoviril.pdfIn PDF document text
    • http://findmecakes.com/userfiles/files/38109282767.pdfIn PDF document text
    • http://hotelborgodeipoeti.com/userfiles/files/7387487073.pdfIn PDF document text
    • http://j1medical.com/uploaded/file/92178602750.pdfIn PDF document text
    • http://psychanalyste-gard.fr/ckfinder/userfiles/files/torerujobalawezedigoloru.pdfIn PDF document text
    • http://conhantaoankhanh.com/webroot/img/files/8648849592.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0d3dc488a---37391211463.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc57be6e2d---jawawujewufobekaside.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/71294212583.pdfIn PDF document text
    • http://neoneofitou.com/ckfinder/userfiles/files/zuwakasofawixawewanubas.pdfIn PDF document text
    • https://kolkataangikar.org/ckfinder/userfiles/files/fevusexegirodufovim.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b503.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB503 16044 bytes
SHA-256: 47bbaac6284836027b3c45c6e9d1dbddcd583e9e3c7d845bdcc4a2ab7ff82b1c
font_01_sfnt_off0000db88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB88 10300 bytes
SHA-256: dd16d9ab3a58a7b81bf85fed5a7f539b429f6b2e040eb6c310ef43794d4ae3c6
font_02_sfnt_off0000f2b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2B3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1